The Tetra Tec filter comes in three sizes PF200, PF300 and PF500. The PF300
is said to pump 300 gallons per hour and is rated for tanks up to 60 gallons.
The advertising for the filter lists its features as having a "Living
Filter" that fills with water and then empties back into the aquarium,
alternately exposing ism the large surface area of the sponge to water and
then air. It claims that its "Tidal Flow" alternating flow return
pulses on an off creating alternating current in the aquarium.

For some time I maintained my Hericthys bocourti show fish in a 30 gallon
long tank. As the fish grew, the two double tetra sponge filters were inadequate
to maintain water quality, so I began to look for a suitable power filter.
I considered a number of models that were on the market. The Tetra Tec really
caught my eye because of one feature it incorporates a heater into the filter.
With a large Central American cichlid in the tank, this is a very attractive
option. Large cichlids are renowned for breaking glass heaters, either by
smashing them against the tank, or by biting them in half! The heater feature,
together with the large size of the filter, convinced me to try out the Tetra
Tec.

The heater module is actually sold as an optional extra. The heater has an
electronic thermostat and auto shut off. Locally, the PF300 sells for about
$80 and the heater module is an additional $40. The Tetra Tec PF300 measures
in at 14 inches long, 8 inches wide, and 9 inches deep. That's a large filter,
particularly for a 300 gallon per hour flow rate. By comparison, the AquaClear
300 is about half the size. The Tetra Tec PF300 requires almost 5 inches of
space between the wall and the back of the tank. It is clearly designed for
a tank larger than 30 gallons, but I needed something that would keep pace
with a large fish in a relatively small tank.

I found setting up the filter to be slightly complicated. I am most familiar
with Hagen Aqua Clear filters, which are very simple. The Tetra Tec has a
few more components and it was necessary to refer to the manual to put it
together. That is not something that comes naturally to most men! However,
after a few minutes, I had the filter assembled and running.

The heater fits into the top of the filter. It has a clearly marked temperature
gauge and I found it very easy to set. When the cover of the filter is in
place, the heater control knob is still accessible. The heater worked very
reliably over the time that I used the filter. On one occasion I discovered
that the water was warmer than required and I observed that the control knob
had been moved to a higher setting. I assume that I inadvertently knocked
it during a filter clean (something to be aware of when working around the
filter).

The filter achieves mechanical and chemical filtration through disposable
filter media cartridges. The aquarium water passes through the coarse mesh
on one side of the cartridge that traps particles suspended in the water.
It then passes through the pocket of the cartridge that contains activated
carbon for the chemical filtration. The water then passes through a fine mesh
on the front side of the cartridge that reportedly "polishes" the
water. The whole process is then repeated as the water passes through the
second bank of cartridges. It utilizes four filter cartridges in two rows
of two. The cartridges fit vertically into slots in the filter. The manual
recommends replacing two pads at a time, and rotating the older pads to the
rear of the filter. The down side of these type of filter cartridges is that
they have to be regularly replaced, unlike the sponge filters used in Hagen
Aquaclear filters. Replacement cartridges cost of about $12 per four pack.
The filter also incorporates a sponge as part of its wet/dry design. The water
constantly rises and falls inside the filter, covering the sponge with water
in one instant, and exposing it to the air in the next. The sponge has large
pores and requires very little maintenance I ran the filter for six months
without rinsing the sponge!

After the filterhas been unplugged for tank maintenance, the water flows out
of it as the tank water is siphoned out. The filter has to be re filled before
it will operate again (it is not self priming). There is often a need to adjust
the flow control knob after cleaning, to ensure that the water "ebbs
and flows". I found this to be a bit of a nuisance in the first few months,
but I soon became accustomed to the adjustments after which I found it quite
easy to get the filter up and running again.

Despite the bulky appearance of the filter, it does not create heavy water
currents in the tank. This allows it to be used on relatively small tanks
without a problem. Whilst the motor is quiet, the filter does tend to make
a splashing type noise due to the ebbing and flowing of the water. The location
of the aquarium would determine whether the noise could pose a problem for
you.

To summarise, I have found the filter to be very suitable for a tank containing
a large cichlid. The integral heater and the rigid intake tube are both good
features when it comes to housing these big fish. If these features were not
needed, such as in a community tank of small fish, the Hagen Aquaclear range
of filters would probably be a better choice. The PF300 is not the simplest
of filters but familiarity speeds up the maintenance process. Finally, it
might not be the best choice for an aquarium that is located in the living
room, as the splashing noises might become a nuisance at times.